The present invention relates to a spring for maintaining in place an electric component, especially a source of current, for instance for an electric timepiece, and for ensuring its electric contact.
Such springs, especially in their applications in the field of the watchmaking, must satisfy a number of conditions which give raise to some difficulties.
They must ensure a sufficient pressure for producing a good electric contact and a good maintaining in place of the electric component in spite of relative large tolerances of fabrication of these components, tolerances which can reach several tenths of mm. This condition means that the mechanical characteristic of the spring must be such that the force exerted by the spring, at least in the useful area, does not vary much with its rise.
It is moreover necessary that, during the deformations of the spring, its points of contact with the bearing element, for instance a frame of a watch-movement, and with the electric component, for instance a battery, move only along one direction, without any lateral movement with respect to the electric component. Such lateral movement would produce a deterioration of the coating surfaces of the bearing element, or of the electric component, conducive to an oxidation reducing the electric contact or even interrupting it.
Such a spring must also be comprised, in plane view, in a relatively small surface, for instance the plane surface of an electric battery used in watchmaking; moreover, the point of application of its force must be situated on an axis of symmetry so that the electric component can be held, on its opposite face, at three points. Its total height, in its condition of maximum of solicitation, that is to say when it is entirely compressed, must be weak and, in its application in the watchmaking, must not go beyond three-tenths of mm, for instance.
The number of its bearing points must not change during the normal solicitations while an accidental solicitation, beyond the maximum but inside the possibilities given by a correct mounting, must neither destroy the spring nor produce therein permanent deformations.
Its cost of manufacture must be the minimum possible.
The object of the present invention is to furnish a spring which responds to all these conditions.